1) Field of the Invention
The present invention relates to a data storage device, especially to a cascade data storage device which enables at least an integrated circuit module (10) to be freely connected by means of a connecting structure.
2) Description of the Prior Art
The Internet era has facilitated information sharing accelerated as well as popularization and progress of information technology. In this regard, a variety of products such as computers and communications & consumer electronics have extensively permeated into consumers' lives.
Recently, the portable data storage device with a data transfer interface and one type of non-volatile memory (for instance, flash memory) integrated has been substantially popularized. On the other hand, a portable device with the USB (Universal Serial Bus) data transfer interface combined which features some advantages such as lightness, portability, and plug-and-play attracts the public's interests.
Accordingly, there are more and more electronic products with USB data transfer interfaces integrated for diversified functions and applications available in the market. These electronic products include but are not limited to USB digital key for vehicles, USB privacy device for protection of digital data (privacy flash disk or electronic device with USB ports), USB automatic homepage guidance device for broadcasting or marketing, USB device with application programs automatically executed, and USB log-in device for public/private websites automatically registered or USB anti-burglar device for electronic devices with USB ports.
However, these mono-functional USB devices hereinabove are not easily stored or even lost or forgotten by one user. Particularly, these function-distinct USB devices have resulted in a user's confused memory or mistaken mix-up due to unclear identification markings corresponding to their functions. These inconveniences hereinbefore unfavorable to a user usually cause unnecessary perplexity.
Additionally, these USB devices limited to specifications for the height of a standard USB male connector have their volumes not further shrunk. In addition to those issues previously mentioned, these increasingly popular USB devices indeed occupy much space owing to restrictions in their own volumes and different USB devices with respective external shapes or sizes.